Buggy code:
public class ReaderBasedJsonParser extends ParserBase { protected static final int [ ] _icLatin1 = CharTypes . getInputCodeLatin1 ( ) ; protected Reader _reader ; protected char [ ] _inputBuffer ; protected boolean _bufferRecyclable ; protected ObjectCodec _objectCodec ; protected final CharsToNameCanonicalizer _symbols ; protected final int _hashSeed ; protected boolean _tokenIncomplete = false ; public ReaderBasedJsonParser ( IOContext ctxt , int features , Reader r , ObjectCodec codec , CharsToNameCanonicalizer st , char [ ] inputBuffer , int start , int end , boolean bufferRecyclable ) { } public ReaderBasedJsonParser ( IOContext ctxt , int features , Reader r , ObjectCodec codec , CharsToNameCanonicalizer st ) { } @ Override public ObjectCodec getCodec ( ) { } @ Override public void setCodec ( ObjectCodec c ) { } @ Override public int releaseBuffered ( Writer w ) throws IOException { } @ Override public Object getInputSource ( ) { } @ Override protected boolean loadMore ( ) throws IOException { } protected char getNextChar ( String eofMsg ) throws IOException { } @ Override protected void _closeInput ( ) throws IOException { } @ Override protected void _releaseBuffers ( ) throws IOException { } @ Override public final String getText ( ) throws IOException { } @ Override public final String getValueAsString ( ) throws IOException { } @ Override public final String getValueAsString ( String defValue ) throws IOException { } protected final String _getText2 ( JsonToken t ) { } @ Override public final char [ ] getTextCharacters ( ) throws IOException { } @ Override public final int getTextLength ( ) throws IOException { } @ Override public final int getTextOffset ( ) throws IOException { } @ Override public byte [ ] getBinaryValue ( Base64Variant b64variant ) throws IOException { } @ Override public int readBinaryValue ( Base64Variant b64variant , OutputStream out ) throws IOException { } protected int _readBinary ( Base64Variant b64variant , OutputStream out , byte [ ] buffer ) throws IOException { } @ Override public final JsonToken nextToken ( ) throws IOException { } private final JsonToken _nextAfterName ( ) { } @ Override public final String nextTextValue ( ) throws IOException { } @ Override public final int nextIntValue ( int defaultValue ) throws IOException { } @ Override public final long nextLongValue ( long defaultValue ) throws IOException { } @ Override public final Boolean nextBooleanValue ( ) throws IOException { } protected final JsonToken _parsePosNumber ( int ch ) throws IOException { } private final JsonToken _parseFloat ( int ch , int startPtr , int ptr , boolean neg , int intLen ) throws IOException { } protected final JsonToken _parseNegNumber ( ) throws IOException { } private final JsonToken _parseNumber2 ( boolean neg , int startPtr ) throws IOException { _inputPtr = ( neg ) ? startPtr + 1 : startPtr ; char [ ] outBuf = _textBuffer . emptyAndGetCurrentSegment ( ) ; int outPtr = 0 ; if ( neg ) { outBuf [ ( outPtr ++ ) ] = '-' ; } int intLen = 0 ; char c = ( ( _inputPtr ) < ( _inputEnd ) ) ? _inputBuffer [ ( ( _inputPtr ) ++ ) ] : getNextChar ( "No<seq2seq4repair_space>digit<seq2seq4repair_space>following<seq2seq4repair_space>minus<seq2seq4repair_space>sign" ) ; if ( c == '0' ) { c = _verifyNoLeadingZeroes ( ) ; } boolean eof = false ; int_loop : while ( ( c >= '0' ) && ( c <= '9' ) ) { ++ intLen ; if ( outPtr >= ( outBuf . length ) ) { outBuf = _textBuffer . finishCurrentSegment ( ) ; outPtr = 0 ; } outBuf [ ( outPtr ++ ) ] = c ; if ( ( ( _inputPtr ) >= ( _inputEnd ) ) && ( ! ( loadMore ( ) ) ) ) { c = ParserMinimalBase . CHAR_NULL ; eof = true ; break int_loop ; } c = _inputBuffer [ ( ( _inputPtr ) ++ ) ] ; } if ( intLen == 0 ) { <START_BUG> reportInvalidNumber ( ( ( "Missing<seq2seq4repair_space>integer<seq2seq4repair_space>part<seq2seq4repair_space>(next<seq2seq4repair_space>char<seq2seq4repair_space>" + ( ParserMinimalBase . _getCharDesc ( c ) ) ) + ")" ) ) ; <END_BUG> } int fractLen = 0 ; if ( c == '.' ) { outBuf [ ( outPtr ++ ) ] = c ; fract_loop : while ( true ) { if ( ( ( _inputPtr ) >= ( _inputEnd ) ) && ( ! ( loadMore ( ) ) ) ) { eof = true ; break fract_loop ; } c = _inputBuffer [ ( ( _inputPtr ) ++ ) ] ; if ( ( c < ( ParserMinimalBase . INT_0 ) ) || ( c > ( ParserMinimalBase . INT_9 ) ) ) { break fract_loop ; } ++ fractLen ; if ( outPtr >= ( outBuf . length ) ) { outBuf = _textBuffer . finishCurrentSegment ( ) ; outPtr = 0 ; } outBuf [ ( outPtr ++ ) ] = c ; } if ( fractLen == 0 ) { reportUnexpectedNumberChar ( c , "Decimal<seq2seq4repair_space>point<seq2seq4repair_space>not<seq2seq4repair_space>followed<seq2seq4repair_space>by<seq2seq4repair_space>a<seq2seq4repair_space>digit" ) ; } } int expLen = 0 ; if ( ( c == 'e' ) || ( c == 'E' ) ) { if ( outPtr >= ( outBuf . length ) ) { outBuf = _textBuffer . finishCurrentSegment ( ) ; outPtr = 0 ; } outBuf [ ( outPtr ++ ) ] = c ; c = ( ( _inputPtr ) < ( _inputEnd ) ) ? _inputBuffer [ ( ( _inputPtr ) ++ ) ] : getNextChar ( "expected<seq2seq4repair_space>a<seq2seq4repair_space>digit<seq2seq4repair_space>for<seq2seq4repair_space>number<seq2seq4repair_space>exponent" ) ; if ( ( c == '-' ) || ( c == '+' ) ) { if ( outPtr >= ( outBuf . length ) ) { outBuf = _textBuffer . finishCurrentSegment ( ) ; outPtr = 0 ; } outBuf [ ( outPtr ++ ) ] = c ; c = ( ( _inputPtr ) < ( _inputEnd ) ) ? _inputBuffer [ ( ( _inputPtr ) ++ ) ] : getNextChar ( "expected<seq2seq4repair_space>a<seq2seq4repair_space>digit<seq2seq4repair_space>for<seq2seq4repair_space>number<seq2seq4repair_space>exponent" ) ;

Fix:
return _handleInvalidNumberStart ( c , neg ) ;